During practice and competition shooting with powder-propelled projectiles at shooting ranges, the shots are aimed at target areas e.g. in the shape of ring-marked square targets or figure-like targets of various sizes and shapes. Behind the targets there is generally a projectile arresting arrangement.
The outdoor type arresting arrangement generally consists of ground masses or gravel being dozed into an elongated bank, or as an alternative, the arrester is a natural slope. The extension of the arrester is determined by the target area, and beyond that, by the regulated safety distances for the type of fire arms used and the manner of shooting. To avoid ricochets from the arresting material in e.g. arresting banks, these are supplemented by projectile-arresting material on the section being shot at. Such a material is carefully selected for the type of shooting and will arrest the projectiles and keep them inside the layer.
This type of projectile arrester has the drawback that the material is unprotected against precipitation, leading to large amounts of unwanted lead and other contaminants from ammunition or stopping material being leached by water and spread in an uncontrolled manner into the surrounding environment. There are environmental demands for limiting these lead emissions, and imperative legislation concerning measures for cleansing of lead from shooting bank. A further problem is the freezing of the projectile-arresting material under extremely cold conditions, caused by large amounts of bound water. This limits the use for safety reasons.
U.S. Pat. No. 5,799,948 (A) discloses a leaching protector which tries to overcome these problems. The leaching protector has on the top surface an elastic layer which, after the passage of the projectile, exhibits a very small entry hole. The projectile is subsequently arrested in the projectile-arresting material beneath it. This material in turn is contained in an enclosed space, having a bottom and sides consisting of a watertight layer, with the projectile-arresting material as a distance material, and with said top surface layer as a water-repelling cover. The enclosed space is drained by a drainage system. This means that surface water which has penetrated the elastic top layer via the minute projectile entry holes, or in other ways, is taken care of by drainage that occurs via the projectile-arresting material down to the bottom layer, where the water due to the inclination flows down to the lowermost point, where the drainage water is filtered to separate the projectile-arresting material from the drainage water, and subsequently the water is collected in a drain pipe, which in turn brings the drainage water by e.g. a closed pipe conduit to an enclosed reservoir or to a filtration plant.
The problem with the leaching protector disclosed in U.S. Pat. No. 5,799,948 (A) is that most of the projectiles penetrate the same area of the covering layer and the rest of the covering layer only receives occasional shots. When a part of the covering layer has received too many holes and patches, a new layer of same material is attached by gluing, and when the patched surfaces become too large, the whole covering layer must be changed. This is due to the fact that when there are large holes in the covering layer rain water enters easily, which increases the volume of unwanted leachate. It is uneconomical to change the whole elastic layer, when only a part of it is damaged. There is thus a need for an improved elastic layer removing the above mentioned disadvantage.